In present machines, such as hydraulic shovels or backhoes, one type of operation routinely employed is a digging operation. Such digging operations include filling a bucket with material, lifting the bucket up by use of a boom, and swinging the bucket toward a truck for dumping the material into the truck. In particular, in large mining environments, one measure of a machine's efficiency is how quickly the machine is capable of acquiring a load of material and then dumping the load into a truck. This is typically known as a cycle or cycle time. A majority of the cycle time consists of the swinging motion of the machine from the dig site to the truck and then back to the dig site. This swing motion can be slowed if a boom up request is made simultaneously with the swing request. Consequently, when both a boom request and a swing request occur together the cycle time is reduced and the productivity of the machine falls.
The boom up and the swing are operated by hydraulic pumps controlled by a hydraulic system. The machine further typically includes an engine cooling fan and a hydraulic cooling fan which are used to ensure that the engine and the hydraulic system are operated within acceptable temperature ranges. The engine cooling fan and the hydraulic cooling fan are driven by hydraulic motors which draw their power from the same hydraulic circuits as that as the hydraulic pumps. There is a considerable amount of power required to drive the cooling fans during operation of the machine. Additionally, operation of these cooling fans at the same time a boom up request and a swing request occur further reduces the productivity of the machine.
In view of the above, it would be desirable to provide a power control system which is capable of determining when both a boom up request and a swing request are occurring to thereby divert power from the cooling fans within the machine to increase the productivity of the machine. Further, it would be advantageous to provide a power control system for a machine which controls operation of the cooling fans within the machine to provide more power to the pumps associated with the boom mechanism and the swing mechanism.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.